Index: clang/lib/AST/RecordLayoutBuilder.cpp
===================================================================
--- clang/lib/AST/RecordLayoutBuilder.cpp
+++ clang/lib/AST/RecordLayoutBuilder.cpp
@@ -2923,12 +2923,17 @@
   ElementInfo Info = getAdjustedElementInfo(FD);
   Alignment = std::max(Alignment, Info.Alignment);
   CharUnits FieldOffset;
+  auto *FieldClass = FD->getType()->getAsCXXRecordDecl();
+  bool PotentiallyOverlapping =
+      FD->hasAttr<NoUniqueAddressAttr>() && FieldClass;
+  bool IsOverlappingEmptyField =
+      PotentiallyOverlapping && FieldClass->isEmpty();
   if (UseExternalLayout)
     FieldOffset =
         Context.toCharUnitsFromBits(External.getExternalFieldOffset(FD));
-  else if (IsUnion)
+  else if (IsUnion || IsOverlappingEmptyField) {
     FieldOffset = CharUnits::Zero();
-  else
+  } else
     FieldOffset = Size.alignTo(Info.Alignment);
   placeFieldAtOffset(FieldOffset);
   Size = std::max(Size, FieldOffset + Info.Size);